RE: [PATCH 1/2] dt-bindings: can: renesas,rcar-canfd: Document renesas,fd-only property

[Biju Das]

Hi Krzysztof Kozlowski,

Thanks for the feedback.

> -----Original Message-----
> From: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> Sent: 20 November 2025 08:09
> Subject: Re: [PATCH 1/2] dt-bindings: can: renesas,rcar-canfd: Document renesas,fd-only property
> 
> On Tue, Nov 18, 2025 at 02:18:34PM +0000, Biju wrote:
> > From: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> >
> > The CANFD on RZ/{G2L,G3E} and R-Car Gen4 support 3 modes FD-Only mode,
> > Classical CAN mode and CAN-FD mode. In FD-Only mode, communication in
> > Classical CAN frame format is disabled. Document renesas,fd-only to
> > handle this mode. As these SoCs support 3 modes, update the
> > description of renesas,no-can-fd property.
> >
> > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > ---
> >  .../bindings/net/can/renesas,rcar-canfd.yaml       | 14 +++++++++++---
> >  1 file changed, 11 insertions(+), 3 deletions(-)
> >
> > diff --git
> > a/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml
> > b/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml
> > index f4ac21c68427..bf9a7d5288d3 100644
> > ---
> > a/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml
> > +++ b/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yam
> > +++ l
> > @@ -125,9 +125,17 @@ properties:
> >    renesas,no-can-fd:
> >      $ref: /schemas/types.yaml#/definitions/flag
> >      description:
> > -      The controller can operate in either CAN FD only mode (default) or
> > -      Classical CAN only mode.  The mode is global to all channels.
> > -      Specify this property to put the controller in Classical CAN only mode.
> > +      The controller can operate in either CAN-FD mode (default) or FD-Only
> > +      mode (RZ/{G2L,G3E} and R-Car Gen4) or Classical CAN mode. Specify this
> > +      property to put the controller in Classical CAN mode.
> > +
> > +  renesas,fd-only:
> > +    $ref: /schemas/types.yaml#/definitions/flag
> > +    description:
> > +      The CANFD on RZ/{G2L,G3E} and R-Car Gen4 SoCs support 3 modes FD-Only
> > +      mode, Classical CAN mode and CAN-FD mode (default). In FD-Only mode,
> > +      communication in Classical CAN frame format is disabled. Specify this
> > +      property to put the controller in FD-Only mode.
> 
> It should really be just an enum since the beginning - representing the mode of operation. Now you
> need to complex oneOf to disallow usage of both.
> 
> You also claim not all devices support this, so you need to disallow it per variant.

OK, I will disallow renesas,fd-only for R-Car Gen3.

Cheers,
Biju